1. Field of the Invention
The present invention relates to a folding drum in a folding machine for use with a rotary press, and more particularly to improvements in a folding drum in a folding machine for use with a rotary press of the type in which a web to be cut on the folding drum is guided and held by means of a plurality of parallel bands aligned in the axial direction of the folding drum over a gap of the folding drum and in which tip end portions of a folding blade are projected to the outside of the folding drum through the gaps between the adjacent bands.
2. Description of the Prior Art
One example of the folding drum in a folding machine for a rotary press of the above-mentioned type will be described with reference to FIGS. 3 and 4.
In these figures, reference numeral 1 designates a generally cylindrical folding drum body, numeral 2 designates a folding blade, numeral 3 designates a pair of folding rollers, numeral 4 designates a needle device, numerals 5 and 6 designate covers, numeral 7 designates a needle receiving rack made of rubber, numeral 8 designates a holder, numeral 9 designates bands, numeral 10 designates a fixed bracket, numeral 11 designates a slide bracket on the folding drum side which can be moved by means of a screw 13, numeral 12 designates a pin, and numerals 14, 15, 16, 17, 18 and 19 designate bolts. In this type of folding machine, a cut web is folded up by means of the folding blade 2 of the folding drum and the pair of folding rollers 3. Within the folding drum body 1 is formed a vacancy 1c for accommodating the folding drum. This vacancy 1c opens at the outer circumferential surface of the folding drum body 1, and this opening is referred to as a "folding drum gap" 1b. Over this folding drum gap 1b are disposed bands 9 as aligned at appropriate intervals in the axial direction of the folding drum body 1 in four or five parallel rows. Respective end portions in the circumferential direction of the folding drum body 1 are mounted to the folding drum body 1 via a fixed bracket 10, and the other end portions in the circumferential direction of the folding drum body 1 are connected to a slide bracket 11 (a bracket that is movable by means of a screw 13) via pins 12. The tip end portions of the folding blade 2 project to the outside of the folding drum through the gaps between these bands 9.
In the folding machine for use with a rotary press in the prior art shown in FIGS. 3 and 4 and described above, though a web to be cut on the folding drum body 1 is guided and held by means of a plurality of the bands 9 aligned in the axial direction of the folding drum body 1 and disposed so as to span the folding drum gap 1b, a folded binder would fluter due to airflows in the folding drum gap 1b and in the gaps between the bands 9. Hence, problems such as end folding were liable to occur, and these problems resulted in unacceptable folded binders.